1. Field of the Invention
The present invention relates to a printed wiring board inspection apparatus for inspecting a printed wiring board using probes. A printed wiring board to be inspected may be any of a printed wiring board mounted with components and a printed wiring board not yet mounted with components.
2. Prior Art
A conventional apparatus for inspecting a printed wiring board from the upper face and the lower face of it has been disclosed in Japanese Patent Laid-Open Publication No.Hei 10-282178. FIG. 5 shows roughly the apparatus disclosed in said patent application. A conventional apparatus 500 is described with reference to the figure. A supporting body 501 is provided with guide rails 502, and a printed wiring board supporting plate 510 is placed on the guide rails 502. A printed wiring board 511 is placed at a specified position on the printed wiring board supporting plate 510. An upper inspection unit 521 is provided above the printed wiring board 511 through an actuator 523 fixed to the supporting body 501. A lower inspection unit 531 is provided below the printed wiring board 511 through an actuator 533 fixed to the supporting body 501.
When inspecting a printed wiring board 511, the printed wiring board 511 is placed on the printed wiring board supporting plate 510 and is carried along the guide rails 502 into the supporting body 501. Next, the upper inspection unit 521 is lowered by the actuator 523, and probes 522 touch and press the upper face of the printed wiring board 511. Next, the lower inspection unit 531 is lifted up by the actuator 533, and probes 532 touch and press the lower face of the printed wiring board 511. The probes 522 and 532 are connected to an unillustrated tester through unillustrated wiring. In this state, the tester gives signals to the printed wiring board 511 through the probes 522 and 532 and at the same time, receives signals from the printed wiring board 511 through the probes 522 and 532. By analyzing said signals, the apparatus inspects the printed wiring board for short circuit or breaking of wires. After the inspection has ended, the lower inspection unit 531 is lowered and then the upper inspection unit 521 is lifted up, and after this, the printed wiring board 511 is taken out.
And the upper inspection unit 521 and the lower inspection unit 531 each are specific to printed wiring boards of a kind to be inspected. In case of inspecting printed wiring boards of another kind, therefore, each of the upper inspection unit 521 and the lower inspection unit 531 must be replaced with another inspecting unit.
However, the above-mentioned prior art has the following problems. First, it needs an actuator which is a driving means for moving up and down an upper inspection unit or a lower inspection unit for each unit. Therefore, the apparatus becomes large and heavy. And since it needs a number of components, there is also a problem that the apparatus increases in assembling man-hour and in component cost.
Second, since there is an actuator for moving up and down the upper inspection unit in the upper part of the apparatus, the upper part of the apparatus is made complicated in structure. As the result, there is a problem that such an upper structure of the apparatus as an actuator and the like hinders a replacing operation at the time of replacing the upper inspection unit and the lower inspection unit with other units.
An object of the present invention is to provide a printed wiring board inspection apparatus which is small in size, light in weight and simple in structure, and makes it easy to replace an upper inspection unit and a lower inspection unit with other units.
According to the present invention, a printed wiring board inspection apparatus for inspecting a printed wiring board by making probes touch the upper face and the lower face of said printed wiring board placed at a specified position, said printed wiring board inspection apparatus comprising;
a supporting body having a printed wiring board holding portion for holding said printed wiring board at a specified position,
an upper unit provided with probes for inspecting the upper face of said printed wiring board,
a lower unit provided with probes for inspecting the lower face of said printed wiring board, and
a single driving means for moving up and down said upper unit and said lower unit, wherein;
said upper unit and said lower unit are held by said supporting body so as to be able to move up and down, and
said driving means moves up and down said upper unit and said lower unit relatively to said supporting body.
And since a driving means for driving an upper unit and a lower unit is moved up and down relatively to a supporting body, the single driving means can move up and down the upper unit and the lower unit by itself. Accordingly, the inspection apparatus can be made small and light.
And in a printed wiring board inspection apparatus of the present invention, said upper unit is composed of an upper member provided with said probes, a lower member joined to said driving means and a coupling member for coupling both of them with each other, and said lower unit is composed of an upper member provided with said probes, a lower member joined to said driving means and a coupling member for coupling both of them with each other.
Therefore, since the coupling members are held so as to be able to move up and down, the upper unit and the lower unit move up and down relatively to the supporting body, namely, to a printed wiring board, and the probes of the upper unit and the lower unit touch the printed wiring board, and thereby the printed wiring board can be inspected. Therefore, in case of inspecting a printed wiring board of another kind, it is enough to replace only the upper member of the upper unit and the upper member of the lower unit with other members.
And since the lower member of the upper unit and the lower member of the lower unit are moved up and down by a driving means provided at the lower part of the apparatus, the upper structure of the inspecting apparatus is made simple.
Furthermore, in a printed wiring board inspection apparatus of the present invention, the sum of the spacing between said lower member of the upper unit and said lower member of the lower unit and the spacing between said upper member of the upper unit and said upper member of the lower unit is kept at a constant value in a process of moving up and down said upper unit and said lower unit.
Accordingly, when the spacing between the lower member of the upper unit and the lower member of the lower unit is made wide by the driving means, the spacing between the upper member of the upper unit and the upper member of the lower unit is made narrow. In other words, the upper unit is lowered by its own weight and the lower unit is lifted by a force from the driving means, and thereby the probes touch a printed wiring board and the apparatus comes into a state where inspection can be performed.
And when the spacing between the lower member of the upper unit and the lower member of the lower unit is made narrow after the inspection has ended, the spacing between the upper member of the upper unit and the upper member of the lower unit is made wide. In other words, the lower unit is lowered by it sown weight and the upper unit is lifted by a force from the driving means, and thereby the probes are detached from the printed wiring board and the apparatus returns to a state before the inspection is started.
And in a printed wiring board inspection apparatus of the present invention, said driving means is disposed between said lower member of the upper unit and said lower member of the lower unit, and moves up and down said upper unit and said lower unit by changing the spacing between said lower member of the upper unit and said lower member of the lower unit.
Accordingly, when the spacing between the lower member of the upper unit and the lower member of the lower unit is made wide by the driving means, the upper unit is lowered by its own weight and the lower unit is lifted by a force from the driving means, and thereby the probes touch a printed wiring board and the apparatus comes into a state where inspection can be performed. And when the spacing between the lower member of the upper unit and the lower member of the lower unit is made narrow after the inspection has ended, the lower unit is lowered by its own weight and the upper unit is lifted by a force from the driving means, and thereby the probes are detached from the printed wiring board and the apparatus returns to a state before the inspection is started.
That is to say, according to the present invention, since a dedicated driving means for driving the upper unit at the time of probing becomes unnecessary, the upper structure of the inspection apparatus is simplified and makes it easy to replace the upper member provided with probes of the upper unit and the upper member with probes of the lower unit with other members.